• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.172-175
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• 2004

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.62-64
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• 2002

No Abstract, See Full-text

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.11a
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• pp.176-180
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• 2004

• Membrane Journal
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• v.12 no.2
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• pp.107-119
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• 2002

Carbon-silica ($C-SiO_2$) membranes can be easily prepared by the pyrolysis of two-phase copolymers containing an aromatic imide block and a siloxane block and remarkably high permselectivities of $He/N_2, O_2/N_2,$ and $CO_2/N_2$. The pyrolysis of the imide-siloxane block copolymers was carried out at different final temperatures, $600^{\circ}C, 800^{\circ}C,$ and $1000^{\circ}C$ under an inert atmosphere, and is the first reported case of the precursors being used for the preparation of carbon membrane. The polymeric precursors were synthesized in a wide range of siloxane content and different final morphology, and the pyrolozed membranes were tested with a high vacuum time-lag method at $25^{\circ}C$ and 76cmHg of feed pressure. In experiments with He, $CO_2, O_2 \;and \;N_2$, the membranes were found to have good $O_2/N_2$ selectivity up to 32.2 and $O_2$ permeability on the order of $10-8/cm^2(STP)cm/cm^2seccmHg.$.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.188-191
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• 2004

Carbon molecular sieve (CMS) membranes have superior gas permeation and separation performance compared with polymeric membranes$^{1.3}$ . Up to now, CMS membranes mostly have been mostly focused on the kinds of precursor and pyrolysis condition (pyrolysis temperature, heating rate, pyrolysis atmosphere).(omitted)

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.36-43
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• 2016

Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, $H_2PtCl_6$ and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of $CaF_2$, LiF, KF and anhydrous potassium hydroxide in $60-70^{\circ}C$ temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range $3.5{\times}10^{-4}{\sim}6.4{\times}10^{-7}S/cm$.

• Membrane Journal
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• v.25 no.4
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• pp.352-357
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• 2015

To determine the pervaporation separation characteristics of 1-butanol/water mixtures, PEI/PDMS hollow fiber membrane module commercialized by Airrane Co. was subjected to both lab and pilot tests. The 1% 1-butanol of 1-butanol/water feed mixture was used. The flux of $133g/m^2hr$ and separation factor of 23.4 at $30^{\circ}C$ were obtained whereas the $505g/m^2hr$ and 5.1 were measured at $50^{\circ}C$. When compared with the performance of the hollow fiber PDMS membrane by Nagasep Co., the higher flux of $10{\sim}20g/m^2hr$ was obtained by the module of Airrane Co. In order to realized the durability of Airrane Co. module, the long-term test of 35 days has been conducted and as a result, the flux $510{\sim}520g/m^2hr$ and separation factor 20~25 were maintained with the initial values.